Separator with control valve and interlock device

ABSTRACT

A centrifugal separator (FIG. 1) has a base adapted to be mounted to a surface of a machine, such as an engine, with internally communicating high pressure liquid lubricant supply and low pressure drain passages. The base includes a control valve to inhibit supply to the rotor via spindle so that the cover and rotor can be removed whilst the base is still connected to the source of high liquid pressure. The valve takes the form of an aperture containing a valve body rotatable by handle to close the supply passage or (FIG. 2) create a diversion passage directly to the drain passage. An interlock device may be provided to impede cover removal with the valve open and/or impede accidental closure of the valve.

TECHNICAL FIELD

This invention relates to liquid cleaning arrangements of the typeincluding a centrifugal separator of solid contaminants from a liquidpassed through a container thereof rotated at high speed, and inparticular relates to mounting and maintaining of such centrifugalseparator with respect to a machine in which said liquid is containedand flows.

BACKGROUND

It is well known to remove solid contaminants of all sizes from a fluid,frequently a liquid, by a centrifugal separator in which a substantiallyvertically-mounted, high speed rotor includes a contaminant-depositingcontainer, (more conveniently referred to simply as a contaminantcontainer) through which the fluid is passed and in which solidcontaminants are separated from the fluid to deposit on the containerwall from which they can be periodically removed or the containerreplaced. Such a centrifugal cleaner may have its rotor driven byexternal coupling to an engine or like rotary plant with which used,which results in a complex and expensive arrangement, or may, as is moreusual, be driven by causing the fluid applied to the contaminantcontainer under pressure to exit by way of tangentially directed nozzlemeans, the reaction to which spins the rotor at high speed essential forefficient centrifugal separation. Such a fluid-cleaner, in which therotor is driven by the fluid being cleaned, is what is referred toherein as a self-powered centrifugal separator.

Such self-powered centrifugal separators are used with internalcombustion engines of a variety of types and sizes to effect separationof particulate contaminants from lubricating oil circulated throughcomponents of any engine by way of ducts formed within the engine block.Examples of such cleaners are to be found in GB 735658, GB 1089355 andGB 2193123.

Self-powered centrifugal separators are, by definition, by-pass devicesin which any lubricating oil which is supplied at substantially the samepressure as to other engine components passes through, and effectsrotation of, the contaminant container by losing all of its energy inthe process and is able only to return to a collecting reservoir of theengine under gravity. Such separators are therefore always employed incombination with conventional full-flow barrier filters by way of whichthe lubricant is pumped at high pressure to the working components ofthe engines, and a proportion of this lubricant is directed to thecentrifugal cleaner.

Traditionally an engine block has been made with a prepared regionadapted to receive a filter assembly thereon, and with ducts surfacingat such regions for supplying lubricant to, and taking it from thefilter assembly. The area of engine block surface that is available formounting an additional centrifugal separator is small and hithertoemphasis has been placed on providing a maximum cross-sectional area fora drain duct, so that lubricant can drain freely under gravity, whileproviding the high pressure supply through an external, but exposed,line.

It is known to make cleaning assemblies incorporating both full-flowbarrier filters and self-powered centrifugal separators in a singlemounting arrangement, having a carrier manifold or block which ismounted on, and forms the interface for liquid passage with, the engineblock. Examples of these are given in GB 876299, GB 2160449 and GB2160796. However, in many engine designs, having existing simple,full-flow filter provisions, it is preferable to have separately mountedfull-flow filter and centrifugal separator.

One of the benefits of employing a centrifugal separator is that thecontainer can operate for long intervals before it becomes filled withsediment requiring the container to be cleaned or replaced. However,even though its operation is not essential to continual operation of theengine, at least in the short term, due to the lubricant by-passing theworking components of the engines, it is still necessary withtraditional designs to clean or replace the container at regularmaintenance times when the engine is stopped, notwithstanding that thecontainer of the centrifugal separator may not need attention (suchattention requires removal of a cover containing the container andreplacement of any seals etc.)

Because the lubricant path through the arrangement by-passes thatsupplying the engine components, it should be possible to remove, cleanand/or change the contaminant container whilst the engine runs, but whenthe container is rotating at high speed and ejecting lubricant withinthe cover this is clearly extremely undesirable. Furthermore, as it isusually a simple matter to determine when a container has stalled, thatis ceased to rotate, through becoming filled with sediment, there is thepossibility of an operative removing the cover in order to remove thestationary container without realizing or remembering that the inlet tothe container is connected to the source of high pressure lubricant forthe engine. Such inadvertent removal of the rotor would not onlydischarge lubricant about the exterior of the engine but also starve theengine components of more lubricant than is normally by-passed by theseparator.

The danger to engine functionality posed by uncontrollable release oflubricant is, of course, also compromised by any high pressure liquidsupply line, exposed externally of the engine, becoming damaged.

Thus whereas such self-powered centrifugal separator arrangementsoperate for long intervals without attention, their presence may involvea small but quantifiable risk of engine damage through accident orinadvertent operation not connected with the functioning of theseparator per se.

Notwithstanding that such an engine is just one example of a machine inwhich liquid, such as a lubricant, is circulated by pump pressure andrequires separation of particulate contaminants, it is an object of thepresent invention to provide, for a machine in which a liquid such aslubricating oil is circulated through internal supply and drain ducts, aself-powered centrifugal separator which offers improved operationalfunctionality and safety than arrangements known hitherto.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention a self-poweredcentrifugal separator of solid contaminants from a liquid lubricant,adapted to be operably mounted against a mounting surface of a machinein which said liquid lubricant is circulated by pumping from areservoir, comprises i) a base having a first surface thereof adapted tobe mounted in an operable disposition against a said mounting surface ofa machine and a second surface arranged with respect to said firstsurface to lie, with said first surface so mounted, to be generallyupwardly facing, ii) a liquid drain passage extending through the basefrom a collection region in said second surface to a surface other thanthe second surface, iii) spindle means extending from said secondsurface of the base along an operably substantially vertical axis abovethe collection region and containing an axially extending spindlepassage, iv) a rotor, supported on the spindle means for rotationthereabouts, having an annular contaminant container in communicationwith the spindle passage and, by way of reaction nozzle means, with thecollection region, said annular contaminant container being operable inresponse to receipt of said pumped liquid lubricant from the spindlemeans at elevated pressure and ejection thereof from the reaction nozzlemeans to effect rotation about the spindle means at such speed as toseparate said solid contaminants from the liquid lubricant within thecontaminant container, v) a removable cover supported on the base andenclosing the rotor and collection region, vi) a liquid lubricant supplypassage extending through the base between said spindle passage and asurface other than said second surface, and vii) control valve meansoperable to permit contemporaneously with supply of pumped liquidlubricant at said elevated pressure to the supply passage in the baseremoval of the rotor.

According to a second aspect of the present invention, a machine inwhich a liquid is circulated includes pump means to develop acirculating pressure in the liquid, a mounting surface and a centrifugalseparator as defined in the preceding paragraph mounted on the mountingsurface.

In a preferred machine arrangement the mounting surface includes asupply and/or drain passage for the liquid and the centrifugal separatoris mounted thereon with the supply and/or drain passage thereof incommunication with a corresponding passage in the mounting surface.

Embodiments of the invention will now be described by way of examplewith reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional elevation through a fragment of a machine in whichlubricating oil is circulated, having high-pressure supply andlow-pressure drain ducts therein opening at a substantially horizontalmounting surface, and a centrifugal separator in accordance with theinvention mounted on said mounting surface, by way of a baseincorporating a liquid inhibiting valve means,

FIG. 2(a) is a sectional elevation through a fragment of a modified formof centrifugal separator illustrating a different form of valve means ina valve-open disposition, and

FIG. 2(b) is a sectional elevation similar to FIG. 2(a) but showing thevalve means in a valve-closed disposition.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIG. 1 a machine 10, such as an internal combustion engineof conventional design, has a block 11 housing moving components whichare lubricated by a liquid lubricant, oil, which is pumped through ductscast or drilled into the block and which also serve to return usedlubricant at atmospheric pressure to a sump or other reservoir. Duct 12is a small diameter, high pressure passage connected to receive liquidsubstantially at pump pressure and duct 13 is a large diameter,atmospheric pressure drain duct connected to the sump. The ducts 12 and13 both open to a substantially flat, horizontal mounting surface 14 onwhich is mounted a centrifugal separator 15, by way of an intermediatesealing gasket 16.

The centrifugal separator 15 comprises a base 17 having a first surface18 adapted to be mounted against the horizontal mounting surface 14 byway of the gasket 16 and a second surface 19, on the opposite side ofthe base, which is generally upwardly facing and recessed to form acollection region 20 which, out of the plane of the drawing, extendscloser towards the first surface as delineated by broken lines 19' andstraddling a central, thicker region 21. A drain passage 22 extendsthrough the base from the collection region 20 to the first surface 18and, with the base mounted, communicating with the drain duct 13.

Spindle means 25 comprises a static spindle fixed to, and extendingfrom, the second surface 19 in the central region 21 along an operably,that is mounted, substantially vertically extending axis 26 above thecollection region. The spindle contains an axially extending spindlepassage 27 open at one end 28 thereof towards the base and at the otherend by way of lateral cross-drillings 29 in the spindle wall.

A rotor 30 supported on the spindle for rotation thereabout comprises abearing tube 31 extending along, and surrounding, the spindle andarranged to receive liquid from the spindle passage by way of crossdrillings 29. The bearing tube also supports, and defines therearound,an annular contaminant container 32, which container is in liquid flowcommunication with the spindle passage by way of apertures 33 in thebearing tube and is in communication with the collection region 20 byway of tangentially directed reaction nozzle means 34 formed in the baseof the container.

A removable cover 35 encloses the rotor and collection region, beingsupported on the base 17 by way of outwardly projecting sealing flanges35' and 17' on each respectively and between which is disposed insealing element 36. The sealing flanges 35' and 17' are taperedconvergingly in a radial direction and surrounded by a correspondinglyprofiled, circumferentially discontinuous clamping ring arrangement 37which, by radial contraction, is operable to provide significant axialsealing force on the sealing element. The upper part of the coversurrounds the upper end part 25' of the spindle and is secured, exertinga limited axially-directed pressure on the sealing element 36, by a nutarrangement 38.

A liquid supply passage 40 extends through the base between the end 28of the spindle passage and said first surface 18, the supply passage, ina manner analogous to drain passage 22, communicating with the duct 12in the mounting surface 17 of the machine block.

The base 17 also has control valve means, indicated generally at 45which will be described in detail below.

Apart from the control valve means, operation of the separator issubstantially conventonal. The drain duct 13 and drain passage 22 are oflarge cross-section and define an ambient pressure within the cover andcollection region at the same pressure as the machine sump, that is,atmospheric pressure. Liquid lubricant, delivered at elevated pressureby duct 12 enters and traverses the base 17 in supply passage 12, passesalong the spindle duct 27 and enters the contaminant container 32 of therotor, wherein the pressure of the liquid is substantially at supplypressure. Liquid is forced from the container by way of reaction nozzlemeans 34 and collects in the collection region 20 from whence it drainsby way of passage 22 and duct 13, the pressure drop across the reactionnozzle means causing sufficient reaction to rotate the rotor at a highrate required to separate particulate contaminants from the liquidpassing through the container 32.

It will be appreciated that the supply of liquid at elevated pressuretakes place through a supply passageway 40 totally contained within thebase 17 and not susceptible to accidental damage.

It will also be appreciated that it is possible for the contaminantcontainer to become filled by separated contaminants and cease rotating,that is, stall. As outlined above, because the centrifugal separatorinherently operates in a by-pass mode its lack of operation for anyreason, including maintenance, does not per se depend upon stopping themachine. Accordingly, there exists a risk of an operative removing thecover from a stalled rotor only to discover that after the rotor isdisplaced, possibly as a result of supply pressure, the liquid isdischarged at high pressure to the detriment of the operative andmachine, possibly starving functioning elements of the machine oflubrication.

The control valve means 45 is operable to permit removal of the rotorcontemporaneously with supply of the liquid to the supply passage 40 inthe base, notwithstanding the elevated pressure due to the machine beingin operation, and operates to inhibit supply of liquid to the spindlepassage at 28. In this embodiment the control valve means is operable toblock the supply passage to the passage of liquid.

The control valve means 45 comprises a valve aperture 46 extendingthrough the base, in particular the thickened central region 21, from athird surface 47 of the base and intersecting the supply passage 40,thereby defining a portion 48 of the supply passage which extends alongthe axis 49 of the aperture between a first section 40' of the supplypassage, which extends from the aperture of the first surface 18, and asecond section 40" of the supply passage which extends from the apertureto the spindle passage.

A valve body 50 extends along the passageway and is displaceable withrespect thereto between a valve-open position (shown) in which itpermits passage of liquid to the spindle passage and a valve-closedposition in which it inhibits the supply of liquid to the spindlepassage.

The valve aperture and valve body are circular in cross-section and thevalve body is rotatable about the common longitudinal axis 49 to effectthe displacement between valve-open and valve-closed positions. Thevalve body is disposed in the aperture such that it closes off thesupply passage section 40' from the section 48, but it has passagewaystherein, in the form of an axially extending recess 51 and a transverseaperture 52 aligned with the end passage section 40', such that in theillustrated rotational position the valve body permits-free flow ofliquid into the aperture portion 48 and supply passage section 40"whereas in other rotational positions the supply passage is blocked.

An end part 55 of the valve body extends from the valve aperture at thethird surface 47 of the base and provides means by which the valve bodymay be rotatably displaced, handle means 56 being secured to this endpart to permit manual displacement.

It will be seen that by movement of the handle means to rotate the valvebody to a valve-closed position, supply of liquid to the spindle passageis blocked at the cover 35 and rotor 32 may be safety removed.

To ensure that the cover is not inadvertently removed when the rotor hasmerely stalled and not as a result of operating the control valve means,interlock means, indicated generally at 60, is provided to impederemoval of the cover whilst the valve means is supplying liquid to thespindle passage, that is, when the valve body 50 is in the valve-openposition.

To this end the cover has a projection conveniently provided at 61 bythe clamping ring arrangement 37 of the cover defining an upwardlyfacing shoulder. The handle means 56 extends from the valve body abovethe level of the projection and carries displaceable abutment means 62,arranged to overlie the shoulder. The interlock means, comprising theabutment means and handle means, thus functions to impede radialexpansion of the clamping ring arrangement, and thus upward removal ofthe cover, unless the abutment means is displaced from the overlyingposition by rotation of the handle means and of the valve body from itsvalve-open position. Although the abutment means may be passive, in thesense that rotation of the handle causes it to cease overlying theprojection with no further action, it is convenient to require a manualoperation to end such overlying relationship, which has the additionaleffect of preventing the valve body being moved from a valve-openposition, or possibly put into a valve-closed position, withoutdeliberate action.

Optionally, and as shown, the valve means 45 may include a cut-off valve70 which is responsive to liquid pressure below a predetermined minimumlevel to prevent liquid from being delivered from the spindle passage.Most conveniently, such cut-off valve is disposed in the base and closesthe supply passage 40. As shown, the cut-off valve 70 is disposed invalve aperture 46 and comprises a piston 71 extending along the apertureand overlying the end of the section 40" of the supply passage, beingbiased by spring 72 towards the valve body and restrained by a shoulder73. In response to liquid pressure in excess of said minimum levelrequired to overcome the bias of spring 72, the piston is displaced topermit liquid passed by the valve body to enter the spindle passage. Theuse of such a cut-off valve per se is known for preventing liquidlubricant from passing through the rotor and by-passing the mainlubrication paths when the supply pressure is too low to sustainrotation. In the present embodiment, the cut-off valve may also providean effective seal to liquid delivery to the spindle passage when thevalve body is in the valve-closed position without placing stringentsealing constraints on the valve body itself. That is, provided thevalve body provides sufficient closure to present a suitably largepressure drop across it, some leakage past the body may be tolerated andthe cut-off valve effect the sealing.

It will be appreciated that many variations may be made in respect ofthe presence or absence of features such as cut-off valve and interlockmeans as well as to the forms taken thereby if present. The relativedisposition of valve body and cut-off valve in respect of the sequencein which supplied liquid encounters them may also be reversed.

Likewise, variation may be made as to the means by which the valve bodyis displaced, whether it be manual or by some powered mechanism, and thenature of the displacement itself, such as rectilinearly instead of, orin addition to, rotation. For example, the ability to translate as wellas rotate the valve body may be incorporated into the interlock meanssuch that the abutment means and handle are displaced along thedirection of aperture axis 49 from a projection-overlying positionwhence the handle can be rotated to place the valve body into a stablevalve-closed position.

In the above described embodiment, the control valve means operatessimply to impede the flow of liquid through the by-pass circuit effectedby the centrifugal separator. In some circumstances the supply pressureof the liquid to all parts of the machine 10 may be interrelated inaccordance with the resistances met by the various flow paths, and itmay be undesirable to upset the relationship by simply blocking thesupply passage.

Referring to FIGS. 2(a) and 2(b), a second form of centrifugal separator80 is shown in part, the parts not shown or shown in full being asdescribed above.

The base 81 differs in detail from the base 7 described above mostparticularly in that the supply passage 82 is centrally disposed andcoaxially surrounded by drain passage 83, both opening into theoperationally downwardly facing and horizontal first surface 84 on theopposite side of the body to upwardly facing second surface 84'.

The control valve means, indicated generally at 85, comprises a valveaperture 86 extending through the base from third surface face 87 andintersecting the supply passage to define a portion 88 thereof by thewidth of the valve aperture.

The valve aperture contains a rotatable valve body 90 extending axiallythereof, through the portion 88 which intersects the supply passage andterminates at end part 91 outwardly of the third surface of the base, towhich end part a handle 92 is secured.

The valve aperture portion 88 separates the supply passage into sections82', communicating with the first surface 84 and 82" communicating, withthe spindle passage. A diversion passage 95 is also defined through thebase joining the valve aperture with drain passage 83.

The valve body 90 has a transverse through-aperture 96 which, in thevalve-open position of the valve body shown in FIG. 2(a) connectssections 82' and 82" of the supply passage, and, in a perpendicularplane has a notch 97 which, in the valve-closed orientation of the valvebody shown in FIG. 2(b) connects supply passage section 92' withdiversion passage 95.

In this arrangement 80, when the valve body is moved to the valve-closedposition, the liquid continues to flow into the by-pass circuit offeredby the centrifugal separator arrangement but is returned directly to thedrain passage permitting the cover and rotor to be removed.

It will be appreciated that this embodiment may also have the valve bodyconfigured for translational motion instead of, or in addition to,rotational rotation. Furthermore, it may also include interlock means toprevent inadvertent removal of the cover and/or operation of the valvemeans and/or it may include a cut-off valve to prevent low-pressuresupply of liquid to the rotor.

It will be appreciated that the presence of a diversion path relaxes therequirement for an efficient sealing mechanism to prevent leakage to thespindle passageway when the valve body is in a valve-closed position. Itmay be possible to have the two sections 92' and 92" of the supplypassage permanently connected, by way of a pressure-responsive cut-offvalve if appropriate, and rely upon reduction in pressure by way ofdiversion of the flow in the valve-closed position to effect inhibitionof supply of liquid to the spindle passage.

It will be appreciated that the valve means or any part of it may bedisposed other than in the base, parts being disposed remotely of thebase or in the spindle means extending from the base.

The mounting surface of the machine with which a centrifugal separatoraccording to the invention is used may, of course, not be horizontal, sothat the first surface of the base would then not be horizontal noroppositely disposed with respect to the second surface.

Furthermore, notwithstanding the operable orientation of the firstsurface, the drain passage and/or supply passage need not both emergefor connection to the machine at the first surface 18 or 84 by which thebase is operably mounted with respect to a machine and with any passagelined up in communication with corresponding ducts in the mountingsurface.

I claim:
 1. A self-powered centrifugal separator of solid contaminantsfrom a liquid lubricant, adapted to be operably mounted against amounting surface of a machine in which said liquid lubricant iscirculated by pumping from a reservoir, said separator comprisingi) abase having a first surface adapted to be mounted in an operabledisposition against said mounting surface of said machine, and a secondsurface arranged with respect to said first surface to lie, with saidfirst surface in said operable disposition, to be generally upwardlyfacing, ii) a liquid drain passage extending through the base from acollection region in said second surface to a surface other than saidsecond surface, iii) spindle means extending from said second surface ofthe base along an operably substantially vertical axis above thecollection region and containing an axially extending spindle passage,iv) a rotor, supported on said spindle means for rotation thereabout,having an annular contaminant container in communication with thespindle passage and, by way of reaction nozzle means, with thecollection region, said annular contaminant container being operable inresponse to receipt of said pumped liquid lubricant from the spindlemeans at elevated pressure and ejection thereof from the reaction nozzlemeans to effect rotation of the annular contaminant container about thespindle means at such speed as to separate said solid contaminants fromthe liquid lubricant within the contaminant container, v) a removablecover supported on the base and enclosing the rotor and collectionregion, vi) a liquid lubricant supply passage extending through the basebetween said spindle passage and a surface other than said secondsurface, and vii) control valve means within said base operable toinhibit passage of liquid lubricant to said spindle passage to permitremoval of the rotor contemporaneously with supply of pumped liquidlubricant at said elevated pressure to the supply passage in the base,and wherein the control valve means comprises a valve aperture extendingthrough the base intersecting, and defining a portion of, said supplypassage, a valve body extending along the valve aperture anddisplaceable with respect thereto between a valve-open position in whichit permits free passage of liquid to said spindle passage and avalve-closed position in which it inhibits supply of liquid to thespindle passage; and further wherein an end part of the valve bodyextends from the aperture at a third surface of the base and the valvebody is displaceable by said end part and further comprises interlockmeans operable to impede removal of the cover while the valve means issupplying liquid to the spindle passage, said interlock means comprisinga projection of the cover defining an upwardly facing shoulder anddisplaceable abutment means arranged to overlie said shoulder to impederemoval of the cover from the base by abutment therewith, saiddisplaceable abutment means being coupled to said end part of the valvebody whereby displacement of said displaceable abutment means from anoverlying position is associated with displacement of the valve bodyfrom a valve-open position.
 2. A self-powered centrifugal separator asclaimed in claim 1 wherein an end part of the valve body extends fromthe aperture at a third surface of the base and the valve body isdisplaceable by said end part and in which, with the valve body disposedin the valve open position, and wherein said control valve meansincludes handle means coupled to said end part of the valve body andarranged to permit manual displacement of the valve body, the handlemeans extending from said end part of the valve body above the positionof said upwardly facing shoulder of the cover and said displaceableabutment means of the interlock means includes said handle means.
 3. Aself-powered centrifugal separator as claimed in claim 1 in which thevalve body is disposed in said valve aperture to close off the supplypassage between said portion and the first surface of the base in bothsaid valve-open and valve-closed positions thereof, said valve bodyhaving at least one passageway therein operable to communicate with saidsupply passage and spindle passage in the valve-open position.
 4. Aself-powered centrifugal separator as claimed in claim 1 in which thevalve body has a passageway therein operable to communicate with saidsupply passage and drain passage in the valve-closed position.
 5. Aself-powered centrifugal separator as claimed in claim 1 in which an endpart of the valve body extends from the aperture at a third surface ofthe base and the valve body is displaceable by said end part.
 6. Aself-powered centrifugal separator as claimed in claim 5 in which thecontrol valve means includes handle means coupled to said end part ofthe valve body and arranged to permit manual displacement of the valvebody.
 7. A self-powered centrifugal separator as claimed in claim 1 inwhich the control valve means includes a cut-off valve disposed betweensaid valve body and the spindle passage and responsive to liquidpressure below a predetermined minimum level to close the supplypassage.
 8. A self-powered centrifugal separator as claimed in claim 7in which the valve aperture defines a said portion of the supply passageextending along the axis of the aperture, the valve body is arranged inits valve-open position to deliver liquid to said axially extendingaperture portion and the cut-off valve comprises a piston, extendingalong said valve aperture and biased towards said valve body to closeoff said spindle passage from the valve aperture, responsive to liquidpressure in excess of said minimum level acting thereon to be displacedagainst the bias to permit the liquid to enter said spindle passage. 9.A self-powered centrifugal separator as claimed in claim 11 in which thecontrol valve means is operable to connect the supply passage to thedrain passage.
 10. A self-powered centrifugal separator as claimed inclaim 11 in which the control valve means includes a cut-off valveresponsive to liquid pressure below a predetermined minimum level toclose the supply passage.
 11. A self-powered centrifugal separator asclaimed in claim 1 in which the control valve means includes interlockmeans operable to impede removal of the cover whilst the valve means issupplying liquid to the spindle means.
 12. A self-powered centrifugalseparator as claimed in claim 1 in which said first surface of the baseis substantially opposite to said second surface.
 13. A self-poweredcentrifugal separator as claimed in claim 1 in which the supply passageopens to said first surface of the base.
 14. A self-powered centrifugalseparator as claimed in claim 13 in which the drain passage also opensto the first surface of the base.
 15. A self-powered centrifugalseparator of solid contaminants from a liquid lubricant, adapted to beoperably mounted against a mounting surface of a machine in which saidliquid lubricant is circulated by pumping from a reservoir, saidseparator comprisingi) a base having a first surface thereof, adapted tobe mounted in an operable disposition against said mounting surface ofsaid machine, and a second surface arranged with respect to said firstsurface to lie, with said first surface so mounted, to be generallyupwardly facing, ii) a liquid drain passage extending through the basefrom a collection region in said second surface to a surface other thansaid second surface, iii) spindle means extending from said secondsurface of the base along an operably substantially vertical axis abovethe collection region and containing an axially extending spindlepassage, iv) a rotor, supported on said spindle means for rotationthereabout, having an annular contaminant container in communicationwith the spindle passage and, by way of reaction nozzle means, with thecollection region, said annular contaminant container being operable inresponse to receipt of said pumped liquid lubricant from the spindlemeans at elevated pressure and ejection thereof from the reaction nozzlemeans to effect rotation of the annular contaminant container about thespindle means at such speed as to separate said solid contaminants fromthe liquid lubricant within the contaminant container, v) a removablecover supported on the base and enclosing the rotor and collectionregion, vi) a liquid lubricant supply passage extending through the basebetween said spindle passage and a surface other than said secondsurface, and vii) control valve means within said base, operable toinhibit passage of liquid lubricant to said spindle passage to permitremoval of the rotor contemporaneously with supply of pumped liquidlubricant at said elevated pressure to the supply passage in the base,and wherein said control valve means further comprises interlock meansoperable to impede removal of the cover whilst the valve means issupplying liquid to the spindle means.